1. Field of the Invention
The present device relates to an automotive part, particularly to a valve core assembly and a compressed gas bypass valve comprising the valve core assembly.
2. Description of the Prior Art
Turbocharging technology is used to ever increasing extents in modern motor vehicles to improve energy efficiency. In a turbocharged engine, exhaust gases drive a turbine in a turbocharger to drive an air compressor, which is connected to the turbine, to compress incoming air. The compressed air reaches a throttle via an intercooler and then enters a cylinder of the engine for combustion. In practical applications, a compressed gas back-flow pipeline, which is connected in parallel to the air compressor, may be provided upstream of the compressed air intercooler, and a compressed gas bypass valve is provided in the compressed gas back-flow pipeline; when the compressed gas bypass valve is not energized, the compressed gas back-flow pipeline is in a closed state and when the compressed gas bypass valve is energized, the compressed gas back-flow pipeline is opened to enable the compressed air to flow back to an inlet end of the air compressor via the compressed gas bypass valve, so that damage to turbine blades caused by shaking due to surges can be prevented, and meanwhile, the back-flow of the compressed gas can also allow the turbine to continue rotating to reduce turbine lag during acceleration and protect the throttle.
In the existing compressed gas bypass valve, to achieve opening and closing of the valve in response to movement of a valve head, the valve head is generally directly connected to an armature in a floating manner, such as the compressed gas bypass valve design set forth in an authorized Chinese patent publication No. CN 203009035 U. Alternately a guide rod is connected to the valve head by an interference fit for transferring a guiding force. The above-mentioned guiding mode in which the valve head is moved directly by the armature has the shortcomings of higher requirements of processing features such as the shape of the armature, and increasing the processing costs; moreover, in the case that the guide rod is in a direct interference connection with the valve head, due to dimensional tolerances of the customer's valve seat and the valve head themselves, the attachment and sealing between the valve head end portion and the customer's valve seat cannot be fully guaranteed, resulting in poor sealing performances; in addition, if there is a gap between the valve head and the guide rod in the axial direction of the guide rod, the valve head would tend to wear.